JP2008175461A - Heat exchanger - Google Patents

Abstract

Heat recovery efficiency can be improved.
In a heat exchanger, heat is exchanged by transferring heat of an exhaust pipe heated by exhaust gas to engine coolant flowing in a flow passage. Here, the leading ends of the introduction pipe 18 for introducing engine cooling water into the flow passage 16 and the discharge pipe 20 for discharging engine cooling water in the flow passage 16 are close to the outer periphery of the exhaust pipe 12. Are arranged. For this reason, the main flow of engine cooling water flowing in the flow passage 16 approaches the outer periphery of the exhaust pipe 12. In addition, since the tips of the introduction pipe 18 and the discharge pipe 20 are arranged close to the outer periphery of the exhaust pipe 12, a gap between the tips of the introduction pipe 18 and the discharge pipe 20 and the outer circumference of the exhaust pipe 12 is created. It is narrower. For this reason, turbulent flow or vortex flow is likely to occur in the engine cooling water flowing through the gap, and the flow on the outer peripheral surface (heat exchange surface) of the exhaust pipe 12 is activated.
[Selection] Figure 1

Description

  The present invention relates to a heat exchanger.

Conventionally, in a double-pipe heat exchanger, in order to introduce a cooling medium into an inner pipe through which a heating medium flows, an outer pipe that forms a flow path for a cooling medium between the inner pipe, and the flow path In addition, there are pipes having an introduction pipe attached to the outer pipe and a discharge pipe attached to the outer pipe for discharging the cooling medium in the flow passage (see, for example, Patent Document 1). In such a double-pipe heat exchanger, heat is exchanged by transferring the heat of the inner pipe to the cooling medium flowing in the flow passage.
JP 2000-130964 A

  However, in the double-pipe heat exchanger as described above, the main flow of the cooling medium in the flow path may flow through the shortest distance between the introduction pipe and the discharge pipe. For this reason, there is a concern that the amount of heat transfer from the inner pipe to the cooling medium is reduced, and the heat recovery efficiency is lowered.

  An object of the present invention is to obtain a heat exchanger capable of improving the heat recovery efficiency in consideration of the above facts.

  The heat exchanger according to the first aspect of the present invention surrounds the inner cylinder member through which the heating medium flows and the outer periphery of the inner cylinder member so as to be separated from each other, and is used for the cooling medium between the inner cylinder member and the inner cylinder member. An outer cylinder member forming a flow path, an introduction pipe attached to the outer cylinder member for introducing a cooling medium into the flow path, and the outer cylinder member for discharging the cooling medium in the flow path And at least one of the introduction pipe and the discharge pipe passes through the peripheral wall of the outer cylinder member, and the tip is disposed close to the outer peripheral portion of the inner cylinder member. It is characterized by that.

  In the heat exchanger according to claim 1, at least one tip of the introduction pipe and the discharge pipe is disposed close to the outer periphery of the inner cylinder member. For this reason, the main flow of the cooling medium flowing in the flow passage approaches the outer periphery of the inner cylinder member. In addition, since the tip of at least one of the introduction tube and the discharge tube is disposed close to the outer periphery of the inner cylinder member, the gap between the at least one tip and the outer periphery of the inner cylinder member is narrowed. For this reason, a turbulent flow or a vortex is likely to occur in the cooling medium flowing through the gap. Thereby, since the amount of heat transfer from the inner cylinder member to the cooling medium can be increased, the heat recovery efficiency can be improved.

  A heat exchanger according to a second aspect of the present invention is the heat exchanger according to the first aspect, wherein the at least one of the heat exchangers expands as a tip portion disposed in the flow passage approaches the inner cylindrical member. It is characterized by being formed with a diameter.

  In the heat exchanger according to claim 2, at least one of the introduction pipe and the discharge pipe is formed to expand in diameter as the tip portion disposed in the flow passage approaches the inner cylinder member. For this reason, the cooling medium passing through the gap between the at least one tip and the outer periphery of the inner cylinder member is likely to flow along the outer periphery of the inner cylinder member. Thereby, since the amount of heat transfer from the inner cylinder member to the cooling medium can be further increased, the heat recovery efficiency can be further improved.

  According to a third aspect of the present invention, there is provided a heat exchanger comprising: an inner cylinder member through which a heating medium flows; and an outer periphery of the inner cylinder member spaced apart from each other; An outer cylinder member forming a flow path, an introduction pipe attached to the outer cylinder member for introducing a cooling medium into the flow path, and the outer cylinder member for discharging the cooling medium in the flow path A discharge that is attached to the upper side of the outer cylinder member, penetrates the peripheral wall of the outer cylinder member, and is arranged in a posture in which the central axis is upward from the horizontal, and a through hole is formed in a part of the peripheral wall disposed in the flow passage And a tube.

  In the heat exchanger according to claim 3, the discharge pipe attached to the upper side of the outer cylinder member is disposed so as to penetrate the peripheral wall of the outer cylinder member and have a central axis upward from the horizontal. The discharge pipe has a through hole formed in a part of the peripheral wall disposed in the flow passage. For this reason, the high-temperature cooling medium that is heated by the heat of the inner cylinder member and moves to the upper side of the flow passage flows into the discharge pipe from the through hole of the discharge pipe, and is discharged from the flow passage. As a result, it is possible to prevent the high-temperature cooling medium from staying on the upper side of the flow path, so that heat recovery efficiency can be improved.

  A heat exchanger according to a fourth aspect of the present invention is the heat exchanger according to the third aspect, wherein the through hole is formed in a portion of the peripheral wall of the discharge pipe opposite to the introduction pipe side. It is characterized by.

  In the heat exchanger according to the fourth aspect, the through hole of the discharge pipe is formed in a portion of the peripheral wall of the discharge pipe opposite to the introduction pipe. For this reason, the cooling medium in the flow passage is likely to generate a flow toward the through hole of the discharge pipe through the gap between the tip of the discharge pipe and the outer periphery of the inner cylinder member. Here, since the cooling medium flows along the outer periphery of the inner cylinder member when passing through the gap, the amount of heat transfer from the inner cylinder member to the cooling medium can be further increased. Therefore, the heat recovery efficiency can be further improved.

  A heat exchanger according to the invention of claim 5 surrounds and surrounds the inner cylinder member having a bent portion while the heating medium flows inside, and the outer periphery of the inner cylinder member on the downstream side of the bent portion, An outer cylinder member that forms a flow path for a cooling medium with the inner cylinder member, an introduction pipe that is attached to the outer cylinder member to introduce the cooling medium into the flow path, A discharge pipe attached to the outer cylinder member for discharging the cooling medium, and at least one of the introduction pipe and the discharge pipe is disposed in proximity to the outer periphery on the large diameter side of the inner cylinder member. It is characterized by that.

  In the heat exchanger according to the fifth aspect, since the bent portion is provided in the inner cylindrical member, the main flow of the heating medium flows on the large diameter side of the inner cylindrical member on the downstream side of the bent portion. For this reason, on the downstream side of the bent portion, the peripheral wall on the large diameter side of the inner cylinder member becomes high temperature. Here, the introduction pipe and the discharge pipe are attached to an outer cylinder member provided on the downstream side of the bent portion of the inner cylinder member. In addition, at least one of the introduction pipe and the discharge pipe (where the main flow of the cooling medium passes) is disposed in the vicinity of the outer periphery (the portion that becomes hot) on the large diameter side of the inner cylinder member. Therefore, since the amount of heat transfer from the inner cylinder member to the cooling medium can be increased, the heat recovery efficiency can be improved.

  As described above, in the heat exchanger according to claim 1 of the present invention, the heat recovery efficiency can be improved.

  In the heat exchanger according to claim 2 of the present invention, the heat recovery efficiency can be further improved.

  In the heat exchanger according to claim 3 of the present invention, the heat recovery efficiency can be improved.

  In the heat exchanger according to claim 4 of the present invention, the heat recovery efficiency can be further improved.

  In the heat exchanger according to claim 5 of the present invention, the heat recovery efficiency can be improved.

<First Embodiment>
FIG. 1 is a side sectional view showing a schematic overall configuration of a heat exchanger 10 according to the first embodiment of the present invention. An arrow UP in FIG. 1 indicates the upper side of the heat exchanger 10.

  The heat exchanger 10 according to the first embodiment is a heat exchanger for exhaust heat recovery for recovering heat of exhaust gas (heating medium) of an engine of an automobile (both not shown) to engine cooling water (cooling medium). For example, it is disposed in a tunnel portion provided on a vehicle body floor portion of an automobile.

  As shown in FIG. 1, the heat exchanger 10 has an exhaust pipe 12 as an inner cylinder member formed in a cylindrical shape. The exhaust pipe 12 is connected to the engine, and the exhaust gas of the engine flows inside. Note that an arrow A in FIG. 1 indicates a direction in which the exhaust gas flows.

  A water jacket 14 as an outer cylinder member formed in a cylindrical shape is provided outside the outer periphery of the exhaust pipe 12. The water jacket 14 is disposed coaxially with the exhaust pipe 12 and surrounds the outer periphery of the exhaust pipe 12 in a spaced manner. Both end portions in the axial direction of the water jacket 14 are drawn and joined to the outer peripheral portion of the exhaust pipe 12. Between the water jacket 14 and the exhaust pipe 12, a flow passage 16 for circulating engine cooling water is provided. Is formed.

  An inlet pipe 18 for introducing engine cooling water into the flow passage 16 and a discharge pipe 20 for discharging engine cooling water from the flow passage 16 are attached to the upper portion of the water jacket 14. The introduction pipe 18 and the discharge pipe 20 are attached to the water jacket 14 so as to penetrate the peripheral wall of the water jacket 14. For this reason, flow path protrusions 18A and 20A that protrude into the flow path 16 are provided on the leading ends of the introduction pipe 18 and the discharge pipe 20, respectively. Further, the tips of the in-flow passage protrusions 18A and 20A (that is, the tips of the introduction pipe 18 and the discharge pipe 20) are arranged close to the outer periphery of the discharge pipe 20, and the introduction pipe 18 and the discharge pipe 20 The inside communicates with the flow passage 16.

  The introduction pipe 18 and the discharge pipe 20 are connected to an engine and a heater core (not shown) at the base end (not shown), and when a water pump (not shown) provided in the engine is operated, the engine cooling water is introduced into the introduction pipe. 18 is introduced into the flow passage 16 via the line 18 (see arrow B in FIG. 1), and the engine coolant in the flow path 16 is discharged through the discharge pipe 20 (see arrow C in FIG. 1). Thereby, engine cooling water circulates among the heat exchanger 10, the engine, and the heater core.

  Next, the operation of the first embodiment will be described.

  In the heat exchanger 10 having the above-described configuration, the heat of the exhaust pipe 12 heated by the exhaust gas is transferred to the engine cooling water flowing in the flow passage 16 to exchange heat, and the exhaust heat is converted into the engine cooling water. Collected. And the engine cooling water which collect | recovered exhaust heat circulates through an engine or a heater core, and exhaust heat is utilized for warming up or heating.

  Here, in this heat exchanger 10, the introduction pipe 18 for introducing the engine cooling water into the flow path 16 and the discharge pipe 20 for discharging the engine cooling water in the flow path 16 have respective tips. It is arranged close to the outer periphery of the exhaust pipe 12. For this reason, the main flow of engine cooling water flowing in the flow passage 16 approaches the outer periphery of the exhaust pipe 12. In addition, since the tips of the introduction pipe 18 and the discharge pipe 20 are arranged close to the outer periphery of the exhaust pipe 12, a gap between the tips of the introduction pipe 18 and the discharge pipe 20 and the outer circumference of the exhaust pipe 12 is created. It is narrower. For this reason, turbulent flow or vortex flow is likely to occur in the engine cooling water flowing through the gap, and the flow on the outer peripheral surface (heat exchange surface) of the exhaust pipe 12 is activated. As described above, since the amount of heat transfer from the exhaust pipe 12 to the engine coolant is increased, the heat exchange efficiency can be improved, and as a result, the heat recovery efficiency can be improved.

  In the first embodiment, the introduction pipe 18 and the discharge pipe 20 are attached to the upper portion of the water jacket 14. However, the attachment positions of the introduction pipe 18 and the discharge pipe 20 are not limited to this, and are appropriately set. Settings can be changed. That is, for example, as shown in FIG. 2, the introduction pipe 18 may be attached to the lower side of the water jacket 14. This also applies to other embodiments of the present invention described below.

  In the first embodiment, the leading ends of both the introduction pipe 18 and the discharge pipe 20 are arranged close to the outer periphery of the exhaust pipe 12. However, the present invention is not limited to this, and the introduction pipe is not limited thereto. 18 and the exhaust pipe 20 are arranged so that one end of the exhaust pipe 20 is disposed close to the outer periphery of the exhaust pipe 12 and the other end of the introduction pipe 18 and the exhaust pipe 20 is disposed apart from the outer periphery of the exhaust pipe 12. May be. This also applies to other embodiments of the present invention described below.

Next, another embodiment of the present invention will be described. In addition, about the structure and effect | action fundamentally similar to the said 1st Embodiment, the same sign as the said 1st Embodiment is provided, and the description is abbreviate | omitted.
<Second Embodiment>
FIG. 3 is a side sectional view showing a schematic overall configuration of a heat exchanger 30 according to the second embodiment of the present invention. The heat exchanger 30 has basically the same configuration as the heat exchanger 10 according to the first embodiment. However, in this heat exchanger 30, the configuration of the introduction pipe 32 and the discharge pipe 34 is different from the introduction pipe 18 and the discharge pipe 20 according to the first embodiment.

  The introduction pipe 32 and the discharge pipe 34 are basically configured in the same manner as the introduction pipe 18 and the discharge pipe 20 according to the first embodiment, but each tip portion (circulation) disposed in the flow passage 16 is arranged. The leading ends of the in-road protrusions 32A and 34A are formed in a flare shape (trumpet shape) that increases in diameter as the exhaust pipe 12 is approached.

  Next, the operation of the second embodiment will be described.

  The heat exchanger 30 having the above configuration has basically the same effects as the heat exchanger 10 according to the first embodiment. Moreover, in this heat exchanger 30, the engine coolant passing through the gaps between the tips of the introduction pipe 32 and the discharge pipe 34 and the outer periphery of the exhaust pipe 12 can easily flow along the outer periphery of the exhaust pipe 12 ( (See arrows D and E in FIG. 3). Therefore, since the amount of heat transfer from the exhaust pipe 12 to the engine coolant can be further increased, the heat recovery efficiency can be further improved.

In the second embodiment, the leading ends of both the introduction pipe 32 and the discharge pipe 34 are formed so as to increase in diameter as they approach the exhaust pipe 12, but the present invention is not limited to this. Only one of the leading ends of the introduction pipe 32 and the discharge pipe 34 may be formed so as to expand in diameter as it approaches the exhaust pipe 12.
<Third Embodiment>
FIG. 4 is a side sectional view showing a schematic overall configuration of a heat exchanger 40 according to the third embodiment of the present invention. The heat exchanger 40 has basically the same configuration as the heat exchanger 10 according to the first embodiment. However, in this heat exchanger 40, a through hole 42 is formed in a part of the peripheral wall of the in-flow passage protrusion 20A of the discharge pipe 20. The through-hole 42 is formed in a portion of the peripheral wall of the in-flow passage protrusion 20A on the introduction pipe 18 side, and is disposed close to the inner peripheral surface of the water jacket 14.

  The discharge pipe 20 according to the third embodiment has the same configuration as that of the first embodiment except for the above, and the central axis around the tip side connected to the water jacket 14 is vertically Arranged along the direction.

  Next, the operation of the third embodiment will be described.

  The heat exchanger 40 having the above configuration has basically the same effects as the heat exchanger 10 according to the first embodiment. Moreover, in this heat exchanger 40, the high-temperature engine coolant that is heated by the heat of the exhaust pipe 12 and moves to the upper side of the flow passage 16 flows from the through hole 42 of the discharge pipe 20 into the discharge pipe 20 ( 4 (see arrow F in FIG. 4), the gas is discharged from the flow path 16. As a result, it is possible to prevent hot engine cooling water from staying on the upper side of the flow passage 16 (between the outer peripheral surface of the in-flow passage protrusions 18A and 20A and the inner peripheral surface of the water jacket 14). Recovery efficiency can be improved.

  Further, after the engine is stopped, the forced circulation of the engine cooling water is stopped by stopping the water pump, but the engine cooling water in the flow passage 16 is heated to a high temperature by the residual heat of the exhaust pipe 12. For this reason, when there is no through-hole 42 in the discharge pipe 20, high-temperature engine coolant may stay in the upper part of the flow passage 16 and boil. In this regard, when the through-hole 42 is formed in the discharge pipe 20 as in the present embodiment, the high-temperature engine cooling water at the top of the flow passage 16 flows into the discharge pipe 20 from the through-hole 42 and naturally. Circulated. Therefore, boiling of the engine cooling water as described above can be prevented.

In the third embodiment, the central axis around the distal end side of the discharge pipe 20 is arranged along the vertical direction. However, the present invention is not limited to this, and the discharge pipe 20 includes the water jacket 14. It is only necessary that the central axis around the tip end side is arranged in a posture upward from the horizontal.
<Fourth Embodiment>
FIG. 5 is a side sectional view showing a schematic overall configuration of a heat exchanger 50 according to the fourth embodiment of the present invention. The heat exchanger 50 has basically the same configuration as the heat exchanger 40 according to the third embodiment, and a through hole 42 is formed in a part of the peripheral wall of the in-flow passage protrusion 20A of the discharge pipe 20. Is formed. However, the through hole 42 is formed in a portion of the peripheral wall of the in-flow passage protrusion 20A on the side opposite to the introduction pipe 18 side.

  Next, the operation of the fourth embodiment will be described.

The heat exchanger 50 having the above configuration has basically the same effects as the heat exchanger 40 according to the third embodiment. Moreover, in the heat exchanger 50, as described above, the through hole 42 of the discharge pipe 20 is formed in a portion of the peripheral wall of the in-flow passage protrusion 20A on the side opposite to the introduction pipe 18 side. For this reason, the engine coolant in the flow passage 16 generates a flow (see arrow G in FIG. 5) that passes through the gap between the tip of the discharge pipe 20 and the outer periphery of the exhaust pipe 12. It becomes easy to do. Here, since the engine coolant flows along the outer periphery of the exhaust pipe 12 when passing through the gap, the amount of heat transfer from the exhaust pipe 12 to the engine coolant can be further increased. Therefore, the heat recovery efficiency can be further improved.
<Fifth Embodiment>
FIG. 6 is a side sectional view showing a schematic overall configuration of a heat exchanger 60 according to the fifth embodiment of the present invention. The heat exchanger 60 has basically the same configuration as the heat exchanger 10 according to the first embodiment. However, in this heat exchanger 60, a bent portion 12 </ b> A is formed at an intermediate portion in the axial direction of the exhaust pipe 12. The water jacket 14 is disposed downstream of the bent portion 12A in the flow of exhaust gas (hereinafter simply referred to as the downstream side), and a part of the downstream side of the bent portion 12A is covered with the water jacket 14. ing. The exhaust pipe 12 is inclined downward on the upstream side of the bent portion 12 </ b> A, and a part (not shown) of the exhaust pipe 12 is disposed below the water jacket 14.

  Furthermore, in the heat exchanger 60, the discharge pipe 20 attached to the water jacket 14 has a tip (tip of the in-flow passage protrusion 20A) on the large diameter side of the bent portion 12A (large diameter side of the exhaust pipe 12, FIG. 6). In FIG.

  Next, the operation of the fifth embodiment will be described.

  The heat exchanger 60 having the above configuration has basically the same effects as the heat exchanger 10 according to the first embodiment. Moreover, in this heat exchanger 60, the bent portion 12A is provided in the exhaust pipe 12, so that the main flow of the exhaust gas flows on the large diameter side of the exhaust pipe 12 on the downstream side of the bent portion 12A (see FIG. 6 arrow H). For this reason, on the downstream side of the bent portion 12A, the peripheral wall on the large diameter side of the exhaust pipe 12 becomes high temperature.

  Here, the tip of the discharge pipe 20 (where the main flow of the engine cooling water always passes) is arranged on the downstream side of the bent portion 12 and in the vicinity of the outer periphery (the portion where the temperature becomes high) of the bent portion 12A. ing. Therefore, since the amount of heat transfer from the exhaust pipe 12 to the engine coolant can be increased, the heat recovery efficiency can be improved.

  In the heat exchanger 60, a part of the exhaust pipe 12 is disposed below the water jacket 14. For this reason, even when some collision object collides with the lower surface of the vehicle body floor portion of the automobile, the collision of the collision object with the water jacket 14 can be suppressed by the exhaust pipe 12 interfering with the collision object.

  In the fifth embodiment, the water jacket 14 is arranged on the downstream side of the bent portion 12A, and a part of the downstream side of the bent portion 12A is covered with the water jacket 14. However, the present invention is not limited to this. Not limited to this, the water jacket 14 may be disposed further downstream than the position shown in FIG. 6, and the bent portion 12 </ b> A may be disposed completely outside the water jacket 14. Further, the water jacket 14 may be arranged on the upstream side of the position shown in FIG. 6, and the entire bent portion 12 </ b> A may be covered with the water jacket 14.

  In the fifth embodiment, the distal end of the discharge pipe 20 arranged on the upstream side of the introduction pipe 18 is arranged close to the outer periphery on the large diameter side of the bent portion 12A. The invention is not limited to this, and by disposing the introduction pipe 18 upstream of the discharge pipe 20 (by replacing the mounting positions of the introduction pipe 18 and the discharge pipe 20), the leading end of the introduction pipe 18 is the bent portion 12A. You may make it the structure arrange | positioned adjacent to the outer periphery of a large diameter side. Further, as described above, when the entire bent portion 12A is covered with the water jacket 14, the leading ends of both the introduction pipe 18 and the discharge pipe 20 are close to the outer periphery on the large diameter side of the bent portion 12A. It may be configured to be arranged in a manner.

Further, in the fifth embodiment, the introduction pipe 18 and the discharge pipe 20 are provided with the in-flow passage protrusions 18A, 20A. However, the present invention is not limited to this, and the in-flow passage protrusion 18A. , 20A may be omitted.
<Sixth Embodiment>
FIG. 7 is a side sectional view showing a schematic overall configuration of a heat exchanger 70 according to the sixth embodiment of the present invention. The heat exchanger 70 has basically the same configuration as the heat exchanger 10 according to the first embodiment. However, in this heat exchanger 70, a cylindrical member 72 formed in a cylindrical shape is interposed between the exhaust pipe 12 and the water jacket 14. The cylindrical member 72 is disposed coaxially with the exhaust pipe 12 and surrounds the outer periphery of the exhaust pipe 12 in a spaced manner. Both ends in the axial direction of the cylindrical member 72 are drawn and joined to the outer peripheral portion of the exhaust pipe 12. Exhaust gas heat exchange is performed between the cylindrical member 72 and the exhaust pipe 12 for flowing the exhaust gas. A path 74 is formed.

  A plurality of exhaust gas introduction holes 76 are formed on the peripheral wall of the exhaust pipe 12 at one end side of the exhaust gas heat exchange path 74 (upstream side of the exhaust gas flow). The interior of the exhaust pipe 12 and the exhaust gas heat exchange path 74 are in communication with each other. A plurality of exhaust gas discharge holes 78 are formed on the peripheral wall of the exhaust pipe 12 on the other end side (downstream side of the exhaust gas flow) of the exhaust gas heat exchange path 74. The interior of the exhaust pipe 12 and the exhaust gas heat exchange path 74 are communicated with each other through 78.

  Further, a valve device 80 is provided in the exhaust pipe 12 between the plurality of exhaust gas introduction holes 76 and the plurality of exhaust gas discharge holes 78. The valve device 80 has a valve body 82 formed in a disc shape, and the valve body 82 is rotatable around a rotation shaft 84. The valve body 82 is rotated around the rotation shaft 84 to thereby have a closed position that closes the inside of the exhaust pipe 12 (exhaust gas flow path 86) and an open position that opens the exhaust gas flow path 86. It is possible to move between.

  On the other hand, in the water jacket 14, both end portions in the axial direction that have been drawn are joined to the outer peripheral portion of the cylindrical member 72, and the circulation for circulating the engine cooling water between the water jacket 14 and the cylindrical member 72. A path 16 is formed. The introduction pipe 18 and the discharge pipe 20 attached to the water jacket 14 are in the same attachment state as in the first embodiment.

  Next, the operation of the sixth embodiment will be described.

  In the heat exchanger 70 configured as described above, when the engine needs to be warmed up, the valve body 82 of the valve device 80 is moved to the closed position. When the valve body 82 is disposed at the closed position, the main flow of exhaust gas is introduced into the exhaust gas heat exchange path 74 through the exhaust gas introduction hole 76 (see arrow J in FIG. 7). The exhaust gas introduced into the exhaust gas heat exchange path 74 is discharged into the exhaust pipe 12 from the exhaust gas discharge hole 78 (see arrow K in FIG. 7), and the main flow of the exhaust gas flows into the exhaust gas heat exchange path 74. Flowing. For this reason, the cylinder member 72 is heated by the exhaust gas flowing in the exhaust gas heat exchange path 74, and the heat of the cylinder member 72 is transmitted to the engine cooling water flowing in the flow passage 16. Thereby, heat exchange between the exhaust gas and the engine cooling water is performed, and basically the same effect as the first embodiment is obtained.

  When the engine is sufficiently warmed, the valve body 82 of the valve device 80 is moved to the open position. When the valve body 82 is disposed at the open position, the main flow of exhaust gas flows through the exhaust pipe 12, and the exhaust gas flowing through the exhaust gas heat exchange path 74 is greatly reduced. As a result, the amount of heat transfer from the cylinder member 72 to the engine cooling water is greatly reduced, and the heat exchange efficiency between the exhaust gas and the engine cooling water is greatly reduced.

  Thus, in this heat exchanger 70, the heat exchange efficiency between the exhaust gas and the engine coolant can be changed by moving the valve body 82 of the valve device 80 between the closed position and the open position. .

  In the first to sixth embodiments, the exhaust gas of the automobile engine is used as a heating medium and the engine cooling water is used as a cooling medium. However, the heating medium and the cooling medium are It may be different.

1 is a side sectional view showing a schematic overall configuration of a heat exchanger according to a first embodiment of the present invention. It is a longitudinal cross-sectional view which shows the modification of the 1st Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the heat exchanger which concerns on the 2nd Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the heat exchanger which concerns on the 3rd Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the heat exchanger which concerns on the 4th Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the heat exchanger which concerns on the 5th Embodiment of this invention. It is a sectional side view which shows the schematic whole structure of the heat exchanger which concerns on the 6th Embodiment of this invention.

Explanation of symbols

10 Heat exchanger 12 Exhaust pipe (inner cylinder member)
12A Bent part 14 Water jacket (outer cylinder member)
16 flow path 18 introduction pipe 20 discharge pipe 30 heat exchanger 32 introduction pipe 34 discharge pipe 40 heat exchanger 42 through hole 50 heat exchanger 60 heat exchanger 70 heat exchanger

Claims (5)

An inner cylinder member through which a heating medium flows;
An outer cylinder member that surrounds and surrounds the outer periphery of the inner cylinder member, and that forms a flow passage for a cooling medium between the inner cylinder member,
An introduction pipe attached to the outer cylinder member for introducing a cooling medium into the flow path;
A discharge pipe attached to the outer cylinder member for discharging the cooling medium in the flow passage;
And at least one of the introduction pipe and the discharge pipe passes through a peripheral wall of the outer cylinder member, and a tip thereof is disposed close to the outer periphery of the inner cylinder member.   2. The heat exchanger according to claim 1, wherein at least one of the tip portions disposed in the flow passage is formed with a diameter increasing as the tip portion approaches the inner cylindrical member. An inner cylinder member through which a heating medium flows;
An outer cylinder member that surrounds and surrounds the outer periphery of the inner cylinder member, and that forms a flow passage for a cooling medium between the inner cylinder member,
An introduction pipe attached to the outer cylinder member for introducing a cooling medium into the flow path;
In order to discharge the cooling medium in the flow passage, it is attached to the upper side of the outer cylinder member, penetrates the peripheral wall of the outer cylinder member, and is arranged in a posture in which the central axis is upward from the horizontal. A discharge pipe having a through-hole formed in a part of the peripheral wall disposed in
Having a heat exchanger.   The heat exchanger according to claim 3, wherein the through hole is formed in a portion of the peripheral wall of the discharge pipe that is opposite to the introduction pipe. An inner cylinder member having a bent portion while the heating medium flows inside;
An outer cylinder member that surrounds and separates the outer periphery of the inner cylinder member on the downstream side of the bent portion, and forms a flow path for a cooling medium between the inner cylinder member;
An introduction pipe attached to the outer cylinder member for introducing a cooling medium into the flow path;
A discharge pipe attached to the outer cylinder member for discharging the cooling medium in the flow passage;
And at least one of the introduction pipe and the discharge pipe is disposed close to the outer periphery of the inner cylinder member on the large diameter side.

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